Bioprocess development for enhanced production of probiotic Bifidobacterium bifidum

The objective of this study was the development of bioprocess for enhanced biomass production of probiotic Bifidobacterium bifidum. In the first process optimization step in Erlenmeyer flasks cultures, different experiments were conducted to study the effect of inoculum volume, inoculum age, temperature and pH of the growth medium on the kinetics of cell growth. In Erlenmeyer flasks cultures, the maximal biomass production was observed with 1% inoculum of 6 log hours at 37 degrees C, and optimal pH of initial media was found to be 6.0. Further positive development in biomass production was observed by scaling up the fermentation process to stirred tank bioreactor. Fermentation was carried out in 2L stirred tank bioreactor, with agitation of 100 rpm and constant temperature of 37 degrees C. The batch culture produced higher biomass of 34.1 g wet cell weight g/l in 12 log hours and viable counts (2.5 x 10(9) CFU/ml) compared to Erlenmeyer flasks. In conclusion, batch cultivation in the 2 l bioreactor with this growth medium under optimal conditions gives enhanced biomass production. However, based on our end result, high-cell density fed-batch and pH control strategies are recommended for the commercial production of B. bifidum as a probiotic.